JP6659247B2 - Connecting body, manufacturing method of connecting body, inspection method - Google Patents

Description

  The present invention relates to a connector in which an electronic component is connected to a transparent substrate, and more particularly to a connector in which an electronic component is connected to a transparent substrate via an adhesive containing conductive particles, a method of manufacturing the connector, and an inspection method. About.

  2. Description of the Related Art Conventionally, liquid crystal display devices and organic EL panels have been used as various display means such as televisions and PC monitors, mobile phones and smartphones, portable game machines, tablet terminals and wearable terminals, and in-vehicle monitors. In recent years, in such a display device, a driving IC is directly mounted on a glass substrate of a display panel by using an anisotropic conductive film (ACF) from the viewpoint of fine pitch, light weight and thinness. A mounting method and a method of directly mounting a flexible substrate on which a drive circuit and the like are formed on a transparent substrate such as a glass substrate are employed.

  On a glass substrate on which an IC or a flexible substrate is mounted, a plurality of transparent electrodes made of ITO (indium tin oxide) or the like are formed, and electronic components such as the IC and the flexible substrate are connected to the transparent electrodes. The electronic component connected to the glass substrate has a plurality of electrode terminals (bumps) formed on the mounting surface corresponding to the transparent electrodes, and is thermocompression-bonded to the glass substrate via an anisotropic conductive film. The electrode terminal and the transparent electrode are connected.

  Anisotropic conductive film is formed by mixing conductive particles into a binder resin to form a film. The resin maintains the mechanical connection between the conductors. As the adhesive constituting the anisotropic conductive film, a highly reliable thermosetting binder resin is usually used, but a photocurable binder resin or a photothermal binder resin may be used.

  When connecting an electronic component to a transparent electrode via such an anisotropic conductive film, first, an anisotropic conductive film is temporarily attached to the transparent electrode of a glass substrate by a temporary crimping means (not shown). Subsequently, the electronic component is mounted on a glass substrate via an anisotropic conductive film to form a temporary connection body, and then the electronic component is transferred to the transparent electrode side together with the anisotropic conductive film by a thermocompression bonding means such as a thermocompression bonding head. Heat and press. The heating by the thermocompression bonding head causes a thermosetting reaction of the anisotropic conductive film, whereby the electronic component is adhered to the transparent electrode.

Japanese Patent No. 4778938 JP 2004-214374 A JP 2005-203758 A

  By the way, in the connection step using this kind of anisotropic conductive film, the heating and pressing step on the connection portion of the electronic component to be connected is not usually performed by heating and pressing over a large area by adding a large number of mounted products. . This is because the connection site of the electronic component has a relatively small area with respect to the electronic component to be connected, and a large number of bumps arranged in the connection site require parallelism. However, this does not apply to the case where productivity is increased by connecting devices having relatively low parallelism requirements collectively.

  Therefore, in the connection step using an anisotropic conductive film, from the viewpoint of improving productivity, in addition to the need to shorten the connection step itself, the inspection step after connection is required with the shortening. Speed is also required.

  The inspection after connection is a step of confirming that the conductive particles are crushed by the bumps of the electronic component and the transparent electrode of the glass substrate to ensure that the conductivity is maintained. It may be performed by an appearance inspection in which indentations of the conductive particles are observed from the back surface of the glass substrate. In addition, as the inspection after the connection, the state of the indentation and the state of the floating or peeling of the adhesive around the indentation are observed by using the human eyes or the captured image.

  By the way, some bumps of electronic parts have bumps formed on the surface of the bump for capturing the conductive particles. However, if the conductive particles are trapped on the bumps having irregularities on the surface, indentations do not sufficiently appear, and even when there is no problem in conductivity, a defect may be determined in the indentation inspection. In addition, when the conductive particles are fitted into the concave portions, the pushing is insufficient, and when the convex portions directly contact the electrodes, the reliability of conduction may be impaired.

  Therefore, an object of the present invention is to provide a connector, a method of manufacturing a connector, and an inspection method capable of determining the quality of conductivity by an indentation inspection and ensuring the reliability of conduction.

In order to solve the above-mentioned problem, the connecting body according to the present invention includes a transparent substrate on which a plurality of terminals are formed, and the transparent substrate via an anisotropic conductive adhesive in which conductive particles are arranged in a binder resin. And an electronic component formed with a plurality of bumps electrically connected to the plurality of terminals and the conductive particles via the conductive particles. The bumps having a height difference of 10% or more of the particle diameter of the conductive particles are formed on the surface capturing the conductive particles, and the height difference from the most protruding protrusion is formed on one bump surface. Has an area that is 20% or more of the particle diameter of the conductive particles, and the area is 70% or less of the bump surface area.

In addition, the method for manufacturing a connector according to the present invention includes mounting an electronic component on a transparent substrate via an adhesive containing conductive particles, pressing the electronic component against the transparent substrate, By curing the adhesive, the method of manufacturing a connector for electrically connecting the bumps formed on the electronic component and the terminals formed on the transparent substrate via the conductive particles, wherein the anisotropic The conductive adhesive is provided such that the conductive particles are independently arranged in a binder resin in a non-contact manner with each other, and the bumps are formed on the surface capturing the conductive particles at a height of 10% or more of the particle diameter of the conductive particles. An uneven portion having a difference is formed, and one bump surface has a region where the height difference from the most protruding position is 20% or more of the particle diameter of the conductive particles, and the region has a bump surface area of 70%. % Or less The is intended.

Further, in the inspection method according to the present invention, the electronic component on which a plurality of bumps are formed is connected via an anisotropic conductive adhesive in which conductive particles are arranged on a transparent substrate on which a plurality of terminals are formed. In the inspection method for inspecting the connection state of the connection body, the anisotropic conductive adhesive, the conductive particles are disposed independently of each other in a binder resin in a non-contact manner, and the bump captures the conductive particles. An uneven portion having a height difference of 10% or more of the particle diameter of the conductive particles is formed on the surface, and the height difference from the most protruding position on one bump surface is 20% of the particle diameter of the conductive particles. % Or more, and the area is 70% or less of the bump surface area, and observing the indentation of the conductive particles contained in the anisotropic conductive adhesive appearing on the terminal of the transparent substrate, Check the connection status of the above electronic components It is intended to 査.

  According to the present invention, bumps having a height difference of 10% or more of the particle diameter of the conductive particles are formed on the bump surface, and the height difference from the most protruding position of the conductive particles on one bump surface is reduced. Since the region that is 20% or more is 70% or less of the bump surface area, even when the conductive particles are captured in the concave portions, the conductive particles can be sufficiently pushed into the concave portions, and the visibility of the indentation is impaired. Therefore, the reliability of the continuity test using the indentation can be ensured.

  Further, even when the conductive particles are captured in the concave portions, the conductive particles are sufficiently pressed in the concave portions, and the convex portions do not directly contact the terminals. Further, since the conductive particles of the anisotropic conductive film are independently arranged in a non-contact manner with each other, the conductive particles can be trapped even at the projections. Therefore, according to the present invention, the reliability of conduction between the bump terminals can be maintained.

FIG. 1 is a cross-sectional view of a liquid crystal display panel shown as an example of a connector. FIG. 2 is a bottom view showing the state of the indentation appearing at the input / output terminal as viewed from the back surface of the transparent substrate. FIG. 3 is a cross-sectional view showing a step of connecting the liquid crystal driving IC and the transparent substrate. FIG. 4 is a plan view showing electrode terminals (bumps) and a space between terminals of the liquid crystal driving IC. FIG. 5 is a cross-sectional view showing a state where conductive particles are sandwiched in a region having a height difference of less than 20% of the particle size of the conductive particles. FIG. 6 is a cross-sectional view showing a state where the conductive particles are sandwiched in a region having a height difference of less than 20% of the particle size of the conductive particles. FIG. 7 is a cross-sectional view showing a state where conductive particles are sandwiched in a region having a height difference of 20% or more of the particle size of the conductive particles. FIG. 8 is a cross-sectional view showing a state where conductive particles are sandwiched in a region having a height difference of 20% or more of the particle size of the conductive particles. FIG. 9 is a sectional view showing the anisotropic conductive film. FIGS. 10A and 10B are diagrams illustrating an anisotropic conductive film in which conductive particles are regularly arranged in a lattice shape. FIG. 10A is a plan view, and FIG. FIGS. 11A and 11B are views showing an anisotropic conductive film in which conductive particles are regularly arranged in a hexagonal lattice, wherein FIG. 11A is a plan view and FIG. 11B is a cross-sectional view. It is a figure which shows the anisotropic film | membrane in which the electrically conductive particle | grains 4 which are not contacted mutually and became independent are irregularly ubiquitous, (A) is a top view, (B) is sectional drawing. It is a figure which shows the anisotropic same garden film in which the electroconductive particle 4 was randomly disperse | distributed, (A) is a top view, (B) is sectional drawing. FIGS. 14A and 14B are plan views showing indentations appearing on terminals. FIG. 14A shows a case where an anisotropic conductive film in which conductive particles are randomly dispersed is used, and FIG. 14B shows a case where conductive particles are arranged. The case where an anisotropic conductive film is used is shown.

  Hereinafter, a connector, a method of manufacturing the connector, and an inspection method to which the present invention is applied will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to only the following embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention. Also, the drawings are schematic, and the ratios of the respective dimensions may be different from actual ones. Specific dimensions and the like should be determined in consideration of the following description. In addition, it is needless to say that dimensional relationships and ratios are different between drawings.

[LCD panel]
Hereinafter, a liquid crystal display panel in which a liquid crystal driving IC chip is mounted as an electronic component on a glass substrate will be described as an example of a connection body to which the present invention is applied. In this liquid crystal display panel 10, as shown in FIG. 1, two transparent substrates 11 and 12 made of a glass substrate or the like are arranged to face each other, and these transparent substrates 11 and 12 are bonded to each other by a frame-shaped seal 13. . The liquid crystal display panel 10 has a panel display 15 formed by enclosing a liquid crystal 14 in a space surrounded by the transparent substrates 11 and 12.

  The transparent substrates 11 and 12 have a pair of striped transparent electrodes 16 and 17 made of ITO (indium tin oxide) or the like formed on both inner surfaces facing each other so as to cross each other. The transparent electrodes 16 and 17 are configured such that a pixel as a minimum unit of a liquid crystal display is formed by the intersection of the transparent electrodes 16 and 17.

  One of the transparent substrates 11 and 12 has a larger planar dimension than the other transparent substrate 11, and an edge 12a of the large transparent substrate 12 is provided as an electronic component. A mounting section 27 on which the liquid crystal driving IC 18 is mounted is provided. As shown in FIGS. 2 and 3, the mounting section 27 includes an input terminal row 20a in which a plurality of input terminals 19a of the transparent electrode 17 are arranged and an output terminal row 20b in which a plurality of output terminals 19b are arranged. A substrate-side alignment mark 31 is formed to overlap the IC-side alignment mark 32 provided on the liquid crystal driving IC 18.

  The liquid crystal driving IC 18 can perform a predetermined liquid crystal display by selectively applying a liquid crystal driving voltage to the pixels to partially change the orientation of the liquid crystal. As shown in FIGS. 3 and 4, the liquid crystal drive IC 18 has an input surface 18 a on the transparent substrate 12 and an input bump 21 a electrically connected to the input terminal 19 a of the transparent electrode 17. An output bump row 22b is formed in which a plurality of output bumps 21b electrically connected to the bump row 22a and the output terminal 19b of the transparent electrode 17 are arranged. As the input bump 21a and the output bump 21b, for example, a copper bump, a gold bump, or a copper bump plated with gold is preferably used.

  For example, the input bumps 21a are arranged in a row along one side edge of the mounting surface 18a, and the output bumps 21b are arranged in a plurality of rows in a staggered manner along the other side edge facing one side edge. ing. The input / output bumps 21a, 21b and the input / output terminals 19a, 19b provided on the mounting portion 27 of the transparent substrate 12 are formed with the same number and pitch, respectively, so that the transparent substrate 12 and the liquid crystal driving IC 18 are aligned. The connection is made by being connected.

  The arrangement of the input / output bumps 21a and 21b is not limited to that shown in FIG. 4, and may be arranged in one or more rows on one side edge and in one or more rows on the other side edge. There may be. Further, in the input / output bumps 21a and 21b, a part of the one-row array may be a plurality of rows, or a part of the plurality of rows may be a single row. Further, the input / output bumps 21a and 21b may be formed in a straight arrangement in which a plurality of rows are parallel and adjacent electrode terminals are parallel, or a plurality of rows are parallel and adjacent electrode terminals are parallel. It may be formed in a staggered arrangement that is evenly displaced.

  In the liquid crystal driving IC 18, the input / output bumps 21a and 21b may be arranged along the long side of the IC substrate, and side bumps may be formed along the short side of the IC substrate. Note that the input / output bumps 21a and 21b may be formed with the same size or different sizes. In the input / output bump rows 22a and 22b, the input / output bumps 21a and 21b formed in the same size may be arranged symmetrically or asymmetrically, and the input / output bumps 21a and 21b formed in different sizes may be arranged asymmetrically. May be done.

  With the recent miniaturization and high performance of liquid crystal display devices and other electronic devices, electronic components such as a liquid crystal driving IC 18 are also required to be small and low in height, and the height of the input / output bumps 21a and 21b is also high. Is low (for example, 6 to 15 μm).

  The IC 18 for liquid crystal driving has an IC-side alignment mark 32 for performing alignment with the transparent substrate 12 by being superimposed on the substrate-side alignment mark 31 on the mounting surface 18a. Since the wiring pitch of the transparent electrodes 17 of the transparent substrate 12 and the fine pitch of the input / output bumps 21a and 21b of the liquid crystal driving IC 18 have been advanced, the liquid crystal driving IC 18 and the transparent substrate 12 are aligned with high precision. Adjustments are required.

  As the substrate-side alignment mark 31 and the IC-side alignment mark 32, various kinds of marks can be used that can align the transparent substrate 12 and the liquid crystal driving IC 18 by being combined.

  A liquid crystal driving IC 18 is connected to the input / output terminals 19a and 19b of the transparent electrode 17 formed on the mounting portion 27 using the anisotropic conductive film 1 as a circuit connection adhesive. The anisotropic conductive film 1 contains the conductive particles 4, and the input / output bumps 21 a and 21 b of the liquid crystal driving IC 18 and the input / output terminal 19 a of the transparent electrode 17 formed on the mounting portion 27 of the transparent substrate 12. 19b is electrically connected through the conductive particles 4. The anisotropic conductive film 1 is thermocompressed by the thermocompression head 33 so that the binder resin is fluidized and the conductive particles 4 are connected to the input / output terminals 19a, 19b and the input / output bumps 21a, 21b of the liquid crystal driving IC 18. And the binder resin is cured in this state. Thereby, the anisotropic conductive film 1 electrically and mechanically connects the transparent substrate 12 and the liquid crystal driving IC 18.

  An alignment film 24 that has been subjected to a predetermined rubbing process is formed on both transparent electrodes 16 and 17, and the initial alignment of liquid crystal molecules is regulated by the alignment film 24. Further, a pair of polarizers 25 and 26 are provided outside the transparent substrates 11 and 12, and the transmitted light from a light source (not shown) such as a backlight is provided by the polarizers 25 and 26. The direction of vibration is regulated.

[Unevenness]
Here, the input / output bumps 21a and 21b of the liquid crystal driving IC 18 are provided on the surface for capturing the conductive particles 4 with uneven portions 28 having a height difference of 10% or more of the particle diameter of the conductive particles 4 before pressing. Have been. As shown in FIGS. 5 and 6, for example, the uneven portions 28 are formed by protruding both side edges or the center of the surface for capturing the conductive particles 4. Further, the height difference between the concave and convex portions 28 refers to the difference between the convex portion 28a most protruding on the surface of the input / output bumps 21a and 21b and the concave portion 28b lower than the convex portion 28a. The height difference of the uneven portion 28 can be measured using, for example, a high-accuracy shape measurement system (trade name: KS-1100, manufactured by Keyence Corporation). The uneven portion 28 is often formed on a side edge portion of the bump surface (see FIG. 5), a central portion of the bump surface (see FIG. 6), or both.

  In the uneven portion 28, the area where the height difference from the most protruding convex portion 28a is 20% or more of the particle diameter of the conductive particles on one bump surface is 70% or less of the bump surface area. As will be described later, since the conductive particles captured by the input / output bumps 21a and 21b are not in contact with each other and are independent of each other, the area where the height difference is 20% or more of the particle diameter of the conductive particles 4 is the bump surface area. By setting the content to 70% or less, even when the conductive particles 4 are captured in the region, the height difference is also captured in a region of less than 20% of the particle size of the conductive particles 4. Therefore, the conductive particles 4 can be sufficiently pushed into the region, and the reliability of the conduction test using the indentation can be improved without impairing the visibility of the indentation. Further, the reliability of conduction between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b can be maintained even by an environmental change after the connection.

  In addition, since the conductive particles 4 can be captured in a region where the height difference is less than 20% of the particle diameter of the conductive particles 4, the conductive particles 4 are sufficiently pushed in the region, and the protrusions 28a are connected to the input / output terminals 19a, 19a. There is no direct contact with 19b. Therefore, the input / output bumps 21a, 21b and the input / output terminals 19a, 19b are conductively connected by sandwiching the conductive particles 4, and good conductive reliability can be maintained even when the environment changes after the connection.

  Further, as will be described later, since the anisotropic conductive film 1 has non-contact and independent conductive particles 4 ubiquitous on the bump surface, the input / output bumps 21a and 21b are also electrically conductive at the protrusion 28a. Sex particles 4 can be captured. Therefore, in the liquid crystal display panel 1, the impressions of the conductive particles 4 captured by the projections 28a appear more clearly, and the reliability of the continuity test using the impressions can be improved. Further, the liquid crystal display panel 1 captures the conductive particles 4 with the projections 28a, thereby maintaining the conduction reliability between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b even when the environment changes after connection. be able to.

  On the other hand, if the region where the height difference of the uneven portions 28 is 20% or more of the particle diameter of the conductive particles 4 before pressing exceeds 70% of the bump surface area, the height difference is less than 20% of the particle size of the conductive particles 4. 7 and FIG. 8, the conductive particles 4 are trapped in a region where the height difference is 20% or more of the particle diameter of the conductive particles 4 as shown in FIGS. Insufficient pressing of the conductive particles 4 causes an increase in conduction resistance. In addition, when an anisotropic conductive film in which conductive particles are randomly dispersed is used, the conductive particles are partially sparse and dense, so that it is assumed that the conductive particles cannot be captured by the projections 28a. In this case, the protrusion 28a directly abuts the input / output terminals 19a, 19b, so that the followability to the change in the distance between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b after connection is low, and the conduction reliability is low. May be impaired.

  Note that the conductive particles 4 in FIG. 7 bite into the concave portion 28b side as an example of a case where the height difference between the input / output bumps 21a and 21b is supplemented by the concave portion 28b in a region where the particle diameter of the conductive particle 4 is 20% or more. It also explains the situation. The hardness varies due to the material variation of the input / output bumps 21a and 21b, and the conductive particles 4 may bite into the input / output bumps 21a and 21b in the pressure bonding process. Also in this case, it can be said that the responsiveness to a change in the distance between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b after connection is reduced, and the conduction reliability may be impaired.

[Occupied area ratio of conductive particles]
The conductive particles 4 have an area ratio to the effective bump area which captures the conductive particles 4 and contributes to the anisotropic conductive connection by overlapping the pair of input / output terminals 19a, 19b and the input / output bumps 21a, 21b. It is preferably at least 10%. Since the conductive particles 4 occupy 10% or more of the effective bump area, the height difference occupying 30% or more of the bump surface area captures many conductive particles in a region where the height difference is less than 20% of the particle diameter. The conductivity by the particles 4 and the visibility of the indentation can be secured.

[Minimum capture number]
As described above, the region having a height difference of 20% or more of the particle diameter of the conductive particles 4 is provided through the anisotropic conductive film 1 in which the conductive particles 4 which are independently present in a non-contact manner are ubiquitous. By connecting the input / output bumps 21a, 21b on which the concave / convex portions 28 having a bump surface area of 70% or less are formed to the input / output terminals 19a, 19b, the liquid crystal display panel 1 can handle one input / output bump 21a, 21b. The minimum capture number of the conductive particles 4 can be 3 or more. Therefore, the liquid crystal display panel 1 can ensure the conductivity of the captured conductive particles 4 and the visibility of the indentation.

[Independent indentation ratio]
In addition, a region having a height difference of 20% or more of the particle diameter of the conductive particles 4 is formed on the bump surface area via the anisotropic conductive film 1 in which the conductive particles 4 which are not in contact with each other and exist independently are ubiquitous. By connecting the input / output bumps 21a and 21b on which the concave / convex portions 28 are set to 70% or less to the input / output terminals 19a and 19b, the liquid crystal display panel 1 can be configured such that the conductive particles existing on one bump surface are formed. The ratio of the independent indentations of No. 4 is 70% or more of the conductive particles 4 trapped in the surfaces of the input / output bumps 21a and 21b. Therefore, the indentation appearing at the input / output terminals 19a and 19b clearly shows the contrast or the curve forming the indentation, and the visibility of each indentation is greatly improved. Thus, the liquid crystal display panel 10 can quickly and accurately inspect the connectivity between the input / output bumps 21a and 21b based on the indentations and the input / output terminals 19a and 19b.

[Anisotropic conductive film]
Next, the anisotropic conductive film 1 will be described. As shown in FIG. 9, an anisotropic conductive film (ACF) 1 generally has a binder resin layer (adhesive layer) 3 containing conductive particles 4 on a release film 2 serving as a base material. It was formed. The anisotropic conductive film 1 is a thermosetting or photo-curing adhesive such as ultraviolet light, and is adhered on input / output terminals 19a and 19b formed on the transparent substrate 12 of the liquid crystal display panel 10 and is provided with a liquid crystal. The driving IC 18 is mounted and fluidized by being heated and pressurized by the thermocompression bonding head 33 so that the conductive particles 4 are opposed to each other, and the input / output terminals 19 a and 19 b of the transparent electrode 17 and the input / output bump 21 a of the liquid crystal driving IC 18 are opposed to each other. , 21b, and the conductive particles are cured in a crushed state by heating or irradiation with ultraviolet rays. Thereby, the anisotropic conductive film 1 can connect the transparent substrate 12 and the liquid crystal driving IC 18 to conduct electricity.

  The anisotropic conductive film 1 has a structure in which conductive particles 4 are regularly arranged in a predetermined pattern on a normal binder resin layer 3 containing a film-forming resin, a thermosetting resin, a latent curing agent, a silane coupling agent, and the like. Are arranged independently of each other in a non-contact manner, and are ubiquitous in the binder resin layer 3.

  The release film 2 supporting the binder resin layer 3 is made of, for example, a release agent such as silicone or the like in PET (Poly Ethylene Terephthalate), OPP (Oriented Polypropylene), PMP (Poly-4-methylpentene-1), PTFE (Polytetrafluoroethylene) or the like. It is applied to prevent drying of the anisotropic conductive film 1 and maintain the shape of the anisotropic conductive film 1.

  As the film-forming resin contained in the binder resin layer 3, a resin having an average molecular weight of about 10,000 to 80,000 is preferable. Examples of the film-forming resin include various resins such as an epoxy resin, a modified epoxy resin, a urethane resin, and a phenoxy resin. Among them, a phenoxy resin is particularly preferable from the viewpoint of a film formation state, connection reliability, and the like.

  The thermosetting resin is not particularly limited, and examples thereof include commercially available epoxy resins and acrylic resins.

  The epoxy resin is not particularly limited, for example, naphthalene type epoxy resin, biphenyl type epoxy resin, phenol novolak type epoxy resin, bisphenol type epoxy resin, stilbene type epoxy resin, triphenol methane type epoxy resin, phenol aralkyl type epoxy resin , Naphthol type epoxy resin, dicyclopentadiene type epoxy resin, triphenylmethane type epoxy resin and the like. These may be used alone or in combination of two or more.

  The acrylic resin is not particularly limited, and an acrylic compound, a liquid acrylate, or the like can be appropriately selected depending on the purpose. For example, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, epoxy acrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, dimethylol tricyclodecane diacrylate, tetramethylene glycol tetraacrylate, 2-hydroxy- 1,3-diacryloxypropane, 2,2-bis [4- (acryloxymethoxy) phenyl] propane, 2,2-bis [4- (acryloxyethoxy) phenyl] propane, dicyclopentenyl acrylate, tricyclo Examples thereof include decanyl acrylate, tris (acryloxyethyl) isocyanurate, urethane acrylate, and epoxy acrylate. In addition, what converted acrylate into methacrylate can also be used. These may be used alone or in combination of two or more.

  The latent curing agent is not particularly limited, but includes, for example, various curing agents such as a heat curing type and a UV curing type. The latent curing agent does not normally react, but is activated by various triggers selected according to applications such as heat, light, and pressure, and starts the reaction. The method of activating the heat-active latent curing agent is to generate active species (cations, anions, radicals) by a dissociation reaction by heating or the like. There are a method of starting a curing reaction by dissolving and dissolving with a resin, a method of starting a curing reaction by eluting a molecular sieve-encapsulated curing agent at a high temperature, and a method of dissolving and curing by microcapsules. Examples of the heat-active latent curing agent include imidazole-based, hydrazide-based, boron trifluoride-amine complex, sulfonium salt, amine imide, polyamine salt, dicyandiamide, and the like, and modified products thereof. A mixture of the above may be used. Among them, a microcapsule-type imidazole-based latent curing agent is preferable.

  Although it does not specifically limit as a silane coupling agent, For example, an epoxy type, an amino type, a mercapto sulfide type, a ureide type, etc. can be mentioned. By adding the silane coupling agent, the adhesiveness at the interface between the organic material and the inorganic material is improved.

[Conductive particles]
Examples of the conductive particles 4 include any known conductive particles used in the anisotropic conductive film 1. Examples of the conductive particles 4 include particles of various metals and metal alloys such as nickel, iron, copper, aluminum, tin, lead, chromium, cobalt, silver, and gold, metal oxides, carbon, graphite, glass, ceramics, and the like. Examples thereof include particles obtained by coating the surface of particles of plastic or the like with a metal, or particles obtained by further coating the surface of these particles with an insulating thin film. When the surface of the resin particles is coated with a metal, examples of the resin particles include an epoxy resin, a phenol resin, an acrylic resin, an acrylonitrile / styrene (AS) resin, a benzoguanamine resin, a divinylbenzene resin, and a styrene resin. Can be mentioned. The size of the conductive particles 4 is preferably 1 to 10 μm, but the present invention is not limited to this.

[Array of conductive particles]
In the anisotropic conductive film 1, conductive particles 4 which are arranged independently of each other in a non-contact manner in a plan view are ubiquitous. For example, the conductive particles 4 are arranged in a predetermined arrangement pattern, and as shown in FIGS. 10A and 11B and FIGS. 11A and 11B, are regularly arranged in a tetragonal lattice or in a hexagonal lattice. It is regularly arranged. The arrangement pattern of the conductive particles 4 can be set arbitrarily. The arrangement distance of such conductive particles 4 can be appropriately adjusted. For example, as shown in FIGS. 12A and 12B, the conductive particles 4 that are not in contact with each other and are independent are irregularly ubiquitous. That is, the arrangement distance may be different depending on the arrangement direction.

  As shown in FIGS. 13A and 13B, the conductive particles 4 are randomly dispersed in the anisotropic conductive film 1 by being arranged independently of each other in a non-contact manner in a plan view, and an aggregate is formed. The conductive particles 4 are captured by the region where the height difference between the input / output bumps 21a and 21b of the uneven portion 28 is less than 20% as compared with the case where the distribution of the conductive particles is uneven due to formation or the like. The conduction reliability can be improved, and the visibility of the indentation appearing on the input / output terminals 19a and 19b in the inspection after the connection of the liquid crystal driving IC 18 can be improved. When the input / output bumps 21a and 21b having the concave and convex portions 28 are sandwiched by the planes, the state of the bump planes can be grasped after the connection by the impression after the connection. Further, by comparing the state of collapse of the conductive particles 4, it is easy to grasp the number of the sufficiently pressed conductive particles 4.

  On the other hand, when the conductive particles are randomly dispersed, the conductive particles caught by the narrowed bumps are small, and the conductive particles are formed in a region where the height difference is less than 20% or in the convex portions 28 a of the uneven portions 28. May be less likely to be trapped, and the conduction reliability may be impaired.

  In addition, the anisotropic conductive film 1 has individual conductive particles 4 in a non-contact and independent manner in a plan view, so that individual conductive particles 4 are individually dispersed as compared with the case where the conductive particles 4 are randomly dispersed. When the same highly integrated liquid crystal driving ICs 18 are anisotropically connected, the blending amount of the conductive particles 4 can be reduced because the probability of the particles 4 being captured is improved. As a result, when the conductive particles 4 are randomly dispersed, the number of conductive particles is required to be a certain amount or more. Such a short circuit can be suppressed by making the state non-contact and independent.

  Further, the anisotropic conductive film 1 has a structure in which even if the conductive particles 4 are densely filled in the binder resin layer 3 due to the ubiquitous independent conductive particles 4 in non-contact with each other in a plan view, the conductive film The generation of the density of the particles 4 is prevented. Therefore, according to the anisotropic conductive film 1, the conductive particles 4 can be trapped even in the input / output terminals 19 a and 19 b and the input / output bumps 21 a and 21 b which are finely pitched.

  Such an anisotropic conductive film 1 is formed, for example, by applying a pressure-sensitive adhesive on a stretchable sheet, arranging the conductive particles 4 in a single layer thereon, and then stretching the sheet at a desired stretching ratio. A method, in which the conductive particles 4 are arranged in a predetermined arrangement pattern on the substrate, and then the conductive particles 4 are transferred to the binder resin layer 3 supported by the release film 2, or the binder supported by the release film 2 It can be manufactured by a method of supplying the conductive particles 4 through an array plate provided with openings according to an array pattern on the resin layer 3.

  The shape of the anisotropic conductive film 1 is not particularly limited. For example, as shown in FIG. 9, the anisotropic conductive film 1 is formed into a long tape shape that can be wound around a take-up reel 6, and is used after being cut by a predetermined length. can do.

  In the above-described embodiment, the anisotropic conductive film 1 is formed of an adhesive film in which independent conductive particles 4 that are not in contact with each other are regularly arranged in a binder resin layer 3 formed into a film shape. Although described in the example, the adhesive according to the present invention is not limited to this. For example, a binder resin in which non-contact and independent conductive particles 4 are ubiquitously formed with an insulating adhesive layer composed of only the binder resin 3 3 can be adopted. Further, if the conductive particles 4 are ubiquitous in a non-contacting and independent state independently of each other, the anisotropic conductive film 1 is arranged in a single layer as shown in FIG. And the conductive particles 4 may be arranged regularly or irregularly in plan view. In addition, the anisotropic conductive film 1 may be one that is singly dispersed at a predetermined distance in at least one layer of a multilayer structure.

[Connection process]
Next, a connection step of connecting the liquid crystal driving IC 18 to the transparent substrate 12 will be described. First, the anisotropic conductive film 1 is temporarily attached on the mounting portion 27 of the transparent substrate 12 on which the input / output terminals 19a and 19b are formed. Next, the transparent substrate 12 is placed on the stage of the connection device, and the liquid crystal driving IC 18 is disposed on the mounting portion 27 of the transparent substrate 12 via the anisotropic conductive film 1.

  Next, the thermocompression bonding head 33 heated to a predetermined temperature at which the binder resin layer 3 is cured is heat-pressed from above the liquid crystal driving IC 18 at a predetermined pressure and time. As a result, the binder resin layer 3 of the anisotropic conductive film 1 exhibits fluidity, flows out between the mounting surface 18a of the liquid crystal driving IC 18 and the mounting portion 27 of the transparent substrate 12, and has a conductive property in the binder resin layer 3. The conductive particles 4 are sandwiched between the input / output bumps 21 a and 21 b of the liquid crystal driving IC 18 and the input / output terminals 19 a and 19 b of the transparent substrate 12 and crushed.

  As a result, the conductive particles 4 are sandwiched between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b to be electrically connected, and in this state, the binder resin heated by the thermocompression bonding head 33 is cured. I do. Thus, it is possible to manufacture the liquid crystal display panel 10 in which conductivity is secured between the input / output bumps 21a and 21b of the liquid crystal driving IC 18 and the input / output terminals 19a and 19b formed on the transparent substrate 12. Further, the pressing of the sandwiched conductive particles 4 (reflection of the crushing of the conductive particles 4) forms indentations in the input / output terminals 19a and 19b.

  The conductive particles 4 that are not between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b are dispersed in the binder resin in the space 23 between the adjacent input / output bumps 21a, 21b, and are electrically insulated. The state is maintained. Therefore, in the liquid crystal display panel 10, electrical continuity is achieved only between the input / output bumps 21 a and 21 b of the liquid crystal driving IC 18 and the input / output terminals 19 a and 19 b of the transparent substrate 12. Note that by using a radical-curing reaction-based fast-curing resin as the binder resin, the binder resin can be rapidly cured even with a short heating time. Further, the anisotropic conductive film 1 is not limited to the thermosetting type, and a photo-setting type or a photo-thermal type adhesive may be used as long as it performs pressure connection.

[Indentation visibility]
When the conductive particles 4 are pressed between the input / output bumps 21a and 21b, the independent indentations 30 can be observed from the transparent substrate 12 side at the input / output terminals 19a and 19b without contact. After the connection of the liquid crystal driving IC 18, the connectivity can be inspected by observing from the back surface of the transparent substrate 12 (the side opposite to the input / output terminals 19 a and 19 b) visually (eg, with a microscope) or by using a captured image.

  The indentation 30 is pressed by the thermocompression bonding head 33 in a state where the conductive particles 4 having high hardness are captured between the input / output bumps 21a, 21b and the input / output terminals 19a, 19b, so that the input / output of the transparent electrode 17 is performed. These are pressing marks of the conductive particles 4 appearing on the terminals 19a and 19b, and are visible when viewed from the back surface side of the transparent substrate 12. The shape of the indentation 30 generally has a diameter equal to or larger than the particle diameter of the conductive particles 4, and is substantially circular as shown in FIG. As shown in FIG. 14B, the shape of the indentation 30 is generally blurred on one side, but most of the shape is formed by a curve. In this case, the curve may be a curve that is 40% or more, preferably 50% or more, and still more preferably 60% or more of a circular shape, that is, a curve that can be recognized as being substantially circular. In the case of metal particles, a linear state may be included.

  The indentations 30 differ in contrast and outer diameter due to the strength of the indentation of the conductive particles 4. Therefore, the indentation serves as an index for determining whether or not the pressing by the thermocompression bonding head 33 is uniformly pressed between the input / output terminals 19a and 19b and within the individual input / output terminals 19a and 19b.

  Here, in the connection body connected using the anisotropic conductive film in which the conductive particles 4 are randomly dispersed in the binder resin layer 3, as described above, the conductive material captured by the narrowed bump is used. In the case where the conductive particles are small and the conductive particles are captured in a region where the height difference is less than 20% or in the convex portion 28a of the uneven portion 28, as shown in FIG. Since the indentations 30 appear irregularly and are close to and overlap with each other, the visibility of the indentations 30 is poor, and it takes time to grasp the state of the indentations 30, so that the inspection takes time and the accuracy of the determination of the indentations 30 decreases. That is, the curve forming the indentation 30 is difficult to identify. Further, in the case of inspection by mechanical image processing, it is difficult to provide a determination criterion because of such poor visibility. Therefore, the accuracy of the determination itself deteriorates. In this case, depending on the resolution, it may look like a combination of straight lines.

  On the other hand, in the liquid crystal display panel 10 according to the present invention, since the conductive particles 4 are formed using the anisotropic conductive film 1 which is arranged independently of each other in a non-contact manner, the input / output terminals 19a and 19b In this case, the conductive particles 4 are sandwiched in a state of being arranged, and as shown in FIG. 14A, the indentations 30 appear regularly in an independent state. Therefore, in the impressions 30 appearing at the input / output terminals 19a and 19b, the contrast or a curve forming the contrast clearly appears, and the visibility of the individual impressions 30 is greatly improved. Thereby, the liquid crystal display panel 10 can quickly and accurately inspect the connectivity between the input / output bumps 21a and 21b based on the indentations 30 and the input / output terminals 19a and 19b.

  If the individual indentations 30 appearing on the input / output terminals 19a and 19b appear independently without contact with each other, visibility can be secured by contrast with a smooth surface on which the conductive particles 4 are not present. May be adjacent to each other, but preferably appear at a predetermined distance, for example, at least 0.2 times the outer diameter, and more preferably at least 0.4 times apart. Note that the contrast with the above-mentioned smooth surface includes a case where the contrast appears as a curve.

  It is preferable that 70% or more of the number of the conductive particles 4 existing in the surface of one input / output terminal 19a, 19b is present in such non-contact and independent indentations 30, more preferably 80%. Or more, still more preferably 90% or more. Non-contact and independent indentations 30 refer to those in which one conductive particle 4 is present, and non-independent ones refer to adjacent or overlapping ones. However, when a large number of conductive particles 4 are intentionally connected and arranged, the units are regarded as independent.

  Next, examples of the present invention will be described. In the present embodiment, the conductive particles are arranged on the bump surface by using an anisotropic conductive film in which conductive particles are independently arranged in non-contact with each other and an anisotropic conductive film in which conductive particles are randomly dispersed. A connection body sample was prepared by connecting an evaluation IC having an uneven portion having a height difference of 20% or more of the particle diameter at a predetermined ratio to a glass substrate for evaluation, and an indentation appearing at each terminal of the glass substrate for evaluation In addition to counting the number, the conduction resistance at the initial stage and after the reliability test, and the incidence of short-circuiting between adjacent bumps were measured.

[Anisotropic conductive film]
The binder resin layer of the anisotropic conductive film used for connection of the evaluation IC is 50 parts by mass of a phenoxy resin (trade name: YP50, manufactured by Nippon Steel Chemical Co., Ltd.) and an epoxy resin (trade name: YL980, manufactured by Mitsubishi Chemical Corporation) 45 parts by mass, 2 parts by mass of a silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts by mass of a cationic curing agent (trade name: SI-60L, manufactured by Sanshin Chemical Co., Ltd.) Was adjusted, and the binder resin composition was applied on a release film and dried in a 70 ° C. oven to form a film having a thickness of 16 μm. In the binder resin layer, conductive particles were arranged at a predetermined particle density or randomly dispersed.

[Evaluation IC for measuring indentation number and conduction resistance]
As an evaluation element for measuring the number of indentations and conduction resistance, an evaluation IC having an outer shape of 0.7 mm × 20 mm, a thickness of 0.2 mm, and a bump (Au-plated); a width of 15 μm × a length of 100 μm, a height of 12 μm, and a bump pitch of 14 μm. Was used.

[Evaluation IC for measuring the incidence of short circuit between bumps]
A comb-teeth TEG (Test Element Group) having a space of 7.5 μm was used as an evaluation element for measuring the occurrence rate of short between bumps.

  The evaluation IC for measuring the number of indentations and conduction resistance, and the evaluation IC for measuring the occurrence ratio of short-circuit between bumps have 70%, 50%, and 30% of the area where the height difference is 20% or more of the conductive particle diameter. %, Respectively.

[Evaluation glass substrate]
As an evaluation glass substrate to which an evaluation IC for measuring the conduction resistance and an evaluation IC for measuring the number of particles captured by the indentation are connected, an outer shape: 30 mm × 50 mm, a thickness of 0.5 mm, an evaluation IC for measuring the conduction resistance An ITO pattern glass (manufactured by Corning Incorporated) having a terminal row in which a plurality of terminals having the same size and the same pitch as the bumps were arranged was used.

  After temporarily attaching an anisotropic conductive film to this glass substrate for evaluation, an IC for evaluation was mounted, and thermocompression bonding was performed at 180 ° C., 80 MPa, and 5 seconds using a thermocompression bonding head to prepare a connector sample. For each of the connection body samples, the number of indentations appearing on the terminals of the glass substrate for evaluation, the initial conduction resistance, the conduction resistance after the reliability test, and the occurrence rate of short-circuit between bumps were measured. The conditions of the reliability test are 85 ° C., 85% RH, and 500 hours.

  For each connection sample to which the evaluation IC was connected, the terminals were observed from the back side of the evaluation glass substrate, and the photographed image was processed with an image processor (WinRoof: manufactured by Mitani Corporation) to obtain the number of indentations and the conductivity. The independent number ratio of particles was determined. In addition, the effective bump area where the pair of terminals and the bumps overlap and contributes to anisotropic conductive connection is determined from the bump width at the time of connection, and based on the conductive particle diameter and the number of indentations, the effective bump area is determined. Was calculated. The bump width at connection indicates the misalignment width between the bump (width 15 μm) and the terminal. When the bump width at connection is 15 μm, there is no misalignment and the entire surface is an effective bump area that contributes to anisotropic conductive connection. . When the bump width at the time of connection is 10 μm, a misalignment of 5 μm occurs between the bump and the terminal, and the effective bump area contributing to anisotropic conductive connection is reduced.

[Example 1]
In Example 1, an anisotropic conductive film in which conductive particles arranged in a hexagonal lattice independently from each other in a non-contact manner with the binder resin layer were used was used. The anisotropic conductive film used in Example 1 was prepared by applying a pressure-sensitive adhesive on a stretchable sheet, and arranging conductive particles on the sheet in a lattice-like and uniform monolayer. In a state where the film was stretched in the above, a binder resin layer was laminated. The conductive particles of the anisotropic conductive film used in Example 1 (trade name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) have a particle diameter of 4 μm and a particle number density of 28,000 pcs / mm ² .

  In Example 1, a bump having a height difference of 10% or more of the particle diameter of the conductive particles was formed on the surface of the bump capturing the conductive particles as an evaluation IC for measuring the number of indentations and the conduction resistance. On the surface of one bump, an evaluation IC was used in which a region where the height difference from the most protruding position was 20% or more of the particle diameter of the conductive particles was 50% of the bump surface area. In addition, the bump width at the time of connection of the connector sample according to Example 1 was 10 μm, and a misalignment of 5 μm occurred.

[Example 2]
In Example 2, a connector sample was manufactured under the same conditions as in Example 1 using the same anisotropic conductive film and evaluation IC as in Example 1. The bump width at the time of connection of the connector sample according to Example 2 was 5 μm, and an alignment deviation of 10 μm occurred.

[Example 3]
In Example 3, a connector sample was manufactured using the same anisotropic conductive film and evaluation IC as in Example 1 under the same conditions as in Example 1. The bump width at the time of connection of the connector sample according to Example 3 was 15 μm, and no misalignment occurred.

[Example 4]
In Example 4, a connector sample was manufactured using the same anisotropic conductive film as in Example 1 under the same conditions as in Example 1. Further, as an evaluation IC for measuring the number of indentations and conduction resistance, a bump portion having a height difference of 10% or more of the particle diameter of the conductive particles is formed on the surface of the bump for capturing the conductive particles. In the above, an evaluation IC was used in which a region where the height difference from the most protruding position was 20% or more of the particle diameter of the conductive particles was 70% of the bump surface area. The bump width at the time of connection of the connector sample according to Example 4 was 10 μm, and a misalignment of 5 μm occurred.

[Example 5]
In Example 5, a connector sample was manufactured under the same conditions as in Example 1 using the same anisotropic conductive film and evaluation IC as in Example 4. The bump width at the time of connection of the connector sample according to Example 5 was 5 μm, and an alignment deviation of 10 μm occurred.

[Example 6]
In Example 6, a connector sample was manufactured using the same anisotropic conductive film as in Example 1 under the same conditions as in Example 1. Further, as an evaluation IC for measuring the number of indentations and conduction resistance, a bump portion having a height difference of 10% or more of the particle diameter of the conductive particles is formed on the surface of the bump for capturing the conductive particles. In the above, an evaluation IC was used in which a region where the height difference from the most protruding position was 20% or more of the particle diameter of the conductive particles was 30% of the bump surface area. The bump width at the time of connection of the connector sample according to Example 6 was 10 μm, and a misalignment of 5 μm occurred.

[Example 7]
In Example 7, a connector sample was manufactured under the same conditions as in Example 4, except that an anisotropic conductive film containing conductive particles having a particle diameter of 3 μm (trade name: AUL703, manufactured by Sekisui Chemical Co., Ltd.) was used. did. The bump width at the time of connection of the connector sample according to Example 7 was 10 μm, and a misalignment of 5 μm occurred.

[Comparative Example 1]
In Comparative Example 1, an anisotropic conductive film in which conductive particles were randomly dispersed in a binder resin layer was prepared by adding and adjusting conductive particles to a binder resin composition, applying the particles on a release film, and baking. Using. The used conductive particles (trade name: AUL704, manufactured by Sekisui Chemical Co., Ltd.) have a particle diameter of 4 μm and a particle number density of 28,000 pcs / mm ² . The evaluation IC and connection conditions are the same as those in the first embodiment. The bump width at the time of connection of the connector sample according to Comparative Example 1 was 10 μm, and a misalignment of 5 μm occurred.

[Comparative Example 2]
In Comparative Example 2, a connector sample was manufactured under the same conditions as Comparative Example 1, except that an anisotropic conductive film having a particle number density of 65000 pcs / mm ² was used. The bump width at the time of connection of the connector sample according to Comparative Example 2 was 10 μm, and a misalignment of 5 μm occurred.

[Comparative Example 3]
In Comparative Example 3, a connector sample was manufactured using the same anisotropic conductive film as Comparative Example 2. Further, as an evaluation IC for measuring the number of indentations and conduction resistance, a bump portion having a height difference of 10% or more of the particle diameter of the conductive particles is formed on the surface of the bump for capturing the conductive particles. In the above, an evaluation IC was used in which a region where the height difference from the most protruding position was 20% or more of the particle diameter of the conductive particles was 70% of the bump surface area. The bump width at the time of connection of the connector sample according to Comparative Example 3 was 10 μm, and a misalignment of 5 μm occurred.

[Comparative Example 4]
In Comparative Example 4, a connector sample was manufactured under the same conditions as Comparative Example 3 except that an anisotropic conductive film containing conductive particles having a particle diameter of 3 μm (trade name: AUL703, manufactured by Sekisui Chemical Co., Ltd.) was used. did. The bump width at the time of connection of the connector sample according to Comparative Example 4 was 10 μm, and an alignment deviation of 5 μm occurred.

  As shown in Table 1, the connected body samples according to Examples 1 to 7 used an anisotropic conductive film in which conductive particles arranged independently of each other in a non-contact manner were ubiquitous, and the height difference was higher than that of the conductive body. Since the area of 20% or more of the conductive particles used the evaluation IC in which the area of the bumps was 70% or less of the surface area of the bumps, the number of indentations and the ratio of the conductive particles to the effective bump area were also 10% or more, and the initial conduction was increased. The resistance was 0.3Ω or less, and the conduction resistance after the reliability test was 3.8Ω or less, indicating good conduction reliability.

  This is because, in the connected body samples according to Examples 1 to 7, there is a region where the height difference is less than 20% of the particle diameter of the conductive particles 4 is 30% or more, and the conductive particles arranged independently and ubiquitously present in the binder resin layer. The conductive particles 4 can be sufficiently pushed in by the conductive particles being captured in the region, and the conduction reliability between the bumps and the terminals can be maintained even by an environmental change after connection. . Further, in the connection body samples according to Examples 1 to 7, the reliability of the conduction test using the indentation could be secured without impairing the visibility of the indentation.

  Furthermore, in the connected body samples according to Examples 1 to 7, by using an anisotropic conductive film in which conductive particles independently arranged in a non-contact manner with each other are ubiquitously used, in a narrowed area between bumps, The occurrence rate of short-circuit between bumps due to continuous conductive particles was 50 ppm or less.

On the other hand, in the connected body samples according to Comparative Examples 1 to 4, since the conductive particles were randomly dispersed, the particle number density was packed as high as 65,000 pcs / mm ² and the height difference was 20% of the conductive particles. Even when an evaluation IC in which the above-mentioned area is 70% or less of the bump surface area is used, the number of indentations is small, the initial conduction resistance is 0.3Ω to 1.4Ω, and the conduction resistance after the reliability test is 2%. As a result, the connection reliability was impaired, from 0.9 Ω to 9.3 Ω.

  This is because, in the connection body samples according to Comparative Examples 1 to 4, the conductive particles are randomly dispersed, so that the density is reduced on the bump surface, and the height difference is less than 20% of the particle diameter of the conductive particles 4. This is because the probability that the conductive particles cannot be captured on the region is high. Further, the region between the bumps narrowed by the aggregate of the conductive particles was continued, and the occurrence rate of short-circuit between the bumps increased to 200 ppm.

  In addition, when the state in which the conductive particles were sandwiched by the bumps was observed by cross-sectional observation of the connection body samples according to Examples 1 to 7, almost the same result as the inspection by the indentation observation was obtained. That is, according to the present invention, it can be understood that the connection reliability can be easily and quickly evaluated by the indentation observation which is a non-destructive inspection, without relying on the cross-sectional observation of the bump which requires man-hours in the destructive inspection.

Reference Signs List 1 anisotropic conductive film, 2 release film, 3 binder resin layer, 4 conductive particles, 6 take-up reel, 10 liquid crystal display panel, 11 and 12 transparent substrate, 12a edge, 13 seal, 14 liquid crystal, 15 panel display Part, 16, 17 transparent electrode, 18 liquid crystal driving IC, 18a mounting surface, 19a input terminal, 19b output terminal, 20a input terminal row, 20b output terminal row, 21a input bump, 21b output bump, 22a input bump row, 22b Output bump array, 23 Terminal space, 27 Mounting part, 28 Uneven part, 28a Convex part, 28b concave part, 31 Substrate alignment mark, 32 IC alignment mark, 33 Thermocompression head

Claims (7)

A transparent substrate on which a plurality of terminals are formed,
A plurality of bumps are formed that are connected to the transparent substrate via an anisotropic conductive adhesive in which conductive particles are disposed in a binder resin, and are electrically connected to the plurality of terminals and the conductive particles. Electronic components,
The conductive particles are independent of each other without contact,
On the surface of the bump that captures the conductive particles, a bump having a height difference of 10% or more of the particle diameter of the conductive particles is formed. A connector having a region where the height difference is 20% or more of the particle diameter of the conductive particles, and the region is 70% or less of the bump surface area.   The connector according to claim 1, wherein a ratio of the conductive particles to an area where the pair of terminals and the bumps overlaps is 10% or more.   3. The connector according to claim 1, wherein the minimum number of the conductive particles captured by one bump is three or more.   The connecting body according to any one of claims 1 to 3, wherein a ratio of independent indentations of the conductive particles is 70% or more of the number of the conductive particles existing on the surface of one bump. Inspection method for inspecting the connection state of a connector connected to an electronic component having a plurality of bumps formed thereon via an anisotropic conductive adhesive in which conductive particles are arranged on a transparent substrate having a plurality of terminals formed thereon At
The anisotropic conductive adhesive, the conductive particles in the binder resin are arranged independently of each other in a non-contact,
On the surface of the bump that captures the conductive particles, a bump having a height difference of 10% or more of the particle diameter of the conductive particles is formed, and the bump from the most protruding position on one bump surface is formed. Having a region where the difference is 20% or more of the particle diameter of the conductive particles, and the region is 70% or less of the bump surface area;
An inspection method for inspecting a connection state of the electronic component by observing indentations of the conductive particles contained in the anisotropic conductive adhesive appearing on terminals of the transparent substrate. Electronic components are mounted on a transparent substrate via an adhesive containing conductive particles,
By pressing the electronic component against the transparent substrate and curing the adhesive, the bumps formed on the electronic component and the terminals formed on the transparent substrate are electrically connected via the conductive particles. In a method of manufacturing a connecting body to be electrically connected,
The anisotropic conductive adhesive, the conductive particles in the binder resin are arranged independently of each other in a non-contact,
On the surface of the bump that captures the conductive particles, a bump having a height difference of 10% or more of the particle diameter of the conductive particles is formed, and the bump from the most protruding position on one bump surface is formed. A method for producing a connector having a region where the difference is 20% or more of the particle diameter of the conductive particles, and the region is 70% or less of the bump surface area.   7. The method for manufacturing a connector according to claim 6, further comprising an inspection step of inspecting a connection state of the connector by observing indentations of the conductive particles from a back surface of the transparent substrate.

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